Which modal verb do you use in the following sentences:
1. You _________ study hard if you want to pass the test.
2. You __________ eat healthy food.
3. You ___________ wear a seat belt.
4. You ___________wash the car, I'll do that.
5. You ____________ eat too much sugar.
6. You _____________ wear a helmet.
should (not)- have to (don't have to)